Intracerebral pneumatocele: CT findings

Two cases of intracerebral pneumatocele following trauma are presented. One to two months after initial treatment both patients had deteriorating neurologic status. The diagnosis was made by radiography. When a pneumatocele is suspected clinically, computed tomography can play a vital role in determining the precise location of the gas collection, its relationship to the fracture site, and the amount of mass effect on the brain.     

Learning by observation requires an early sleep window

Numerous studies have shown that sleep enhances memory for motor skills learned through practice. Motor skills can, however, also be learned through observation, a process possibly involving the mirror neuron system. We investigated whether motor skill enhancement through prior observation requires sleep to follow the observation, either immediately or after a delay, to consolidate the procedural memory. Sequence-specific fingertapping performance was tested in 64 healthy subjects in a balanced design. Electromyography verified absence of overt or subliminal hand muscle activations during observation. The results show that immediate sleep is necessary for the enhancement of a motor skill through prior observation. Immediate sleep improved the speed of subsequent performance by 22 ± 11% (mean ± SEM) (P = 0.04) and reduced the error rate by 42 ± 19% (P = 0.02). In contrast, no performance gains occurred if sleep was initiated more than 12 h after observation. A second study on 64 subjects ruled out explicit familiarity with the sequence or the spatiotemporal rhythm of the sequence to underlie performance improvements. The sleep-dependent observational motor learning enhancement is at least similar to that previously reported for implicit and declarative memory. The apparent prerequisite of observing real movements indicates that subjects transfer experience obtained through observation of movements to subsequent self-initiated movements, in the absence of practice. Moreover, the consolidation of this transfer requires an early sleep window. These findings could improve learning new motor skills in athletes and children, but also in patients having to remaster skills following stroke or injury.     

Histiocytic erythema multiforme

Erythema multiforme is histologically characterized by liquefactive degeneration along the dermal-epidermal junction, necrotic keratinocytes and a lymphocytic infiltrate. We report a 10-year-old boy with recurrent erythema multiforme major of undetermined etiology with unusual histologic findings. A skin biopsy taken at day 2 of his eruption revealed histologic features otherwise characteristic of erythema multiforme, but mediated instead by a CD68-positive infiltrate, resembling cutaneous Kikuchi's disease. To the best of our knowledge this is the first reported case of 'histiocytic' erythema multiforme.     

Association of the subtype 2 of the Epstein-Barr virus with T-cell non- Hodgkin's lymphoma of the midline granuloma type [see comments]

Lethal midline granuloma (LMG) is associated with Epstein-Barr virus (EBV). The latter has at least two subtypes with different biological properties. The subtypes can be identified by their genomic configuration. Using EBV-RNA (EBER) in situ hybridization and EBV polymerase chain reaction (PCR), we have looked for the presence of EBV in six LMGs and six non-Hodgkin's lymphomas (NHLs) located in the nasopharyngeal region, and determined the subtype of EBV. Six of six LMGs were positive by PCR and EBER in situ hybridization, whereas NHLs were either negative or, in three of six cases, showed few EBER- positive cells considered to be nonneoplastic lymphocytes. The subtype 2 was found in LMG lesions of three of six patients; the remaining three of six patients with LMG had the generally occurring subtype 1. The results indicate that the association of EBV with NHL may depend more on tumor type than on its localization. The occurrence of the rare subtype 2 in LMG may relate to a covert immune defect.     

Radiotherapy for melanotic freckles

Five patients who received radiotherapy (RT) for 7 melanotic freckles (MF, also known as Hutchinson's freckles, lentigo maligna) were reviewed 8 to 37 months after their treatment by RT. Local control and a favourable cosmetic result occurred in all patients. Treatment toxicity was minimal. Few reports about the use of RT for MF exist. Many other treatments including observation alone have been associated with high rates of recurrence, and in some cases conversion to invasive melanoma has occurred. RT appears to be a safe and effective treatment for this condition, providing that doses equivalent to 44 Gy in 11 fractions or more are given.     

Corpus luteum function after tubal sterilization using endothermic coagulation

Following various methods of tubal sterilization, menstrual disturbance have been reported. One reason for these might be a change in ovarian function caused by interruption of blood supply or nervous supply to the organ. In order to prospectively evaluate the corpus luteum function following tubal sterilization, plasma progesterone determinations were made during one menstrual period 2-3 months and even years after the operation performed by means of endothermic coagulation. The levels of progesterone in plasma during the menstrual period before the operation were used for comparison. When using endothermic coagulation as a method of sterilization there seem to be no signs of changed corpus luteum function either, months or years after the operation.     

Splenic mesothelial cysts at laparoscopy

One case of splenic mesothelial cyst formation fortuitously found and biopsied during laparoscopic operation is described.